The mother of two, whose greatest political achievement is opening a center for autistic children in the capital, is the wife of current President Ricardo Martinelli. She's also his party’s vice presidential candidate in the most closely watched presidential vote in two decades.

The Constitution bars President Martinelli from running for reelection until five years from now, though he’s said he would like to change that. It also bans a sitting president’s blood relatives from seeking the nation’s top two jobs, though there are lawyers who argue spouses are a legally gray area.

Some see the prospect of another de-facto Martinelli presidency as too close to a history that Central America’s most cosmopolitan nation, sandwiched between Costa Rica and Colombia, thought it had left behind. Panama's two decades of military dictatorship still resonate here, and since the United States deposed drug-running Gen. Manuel Noriega in 1989, Panamanians have never elected the same political party for two consecutive terms.

“If Martinelli repeats through this covered-up re-election, we fear we’ll be back in civilian dictatorship mode,” Mr. Eisenmann says.

Martinelli’s handpicked successor for his Democratic Change party is a relative political novice as well. Jose Domingo Arias runs his father-in-law’s clothing company, and was the housing minister in Martinelli’s government.

Many say it’s simply a way for Martinelli, a supermarket magnate, to cling to power until he can run again. Ms. Linares’s notable absence on the campaign trail, which her husband has dominated, has only cemented that perception.

“There’s no question that Martinelli will remain very influential,” says Risa Grais-Targow, a Latin American analyst at Eurasia Group, which projects a narrow Arias win as voters go to the polls today. “An Arias government is essentially a Martinelli government.”

It’s a familiar narrative in Latin America. Xiomara Castro de Zelaya, wife of deposed Honduran president Manuel Zelaya, ran for president last year, but lost. Argentina’s Cristina Fernandez de Kirchner replaced her husband, Nestor Kirchner, as president. Many believe Rosario Murillo, Nicaraguan President Daniel Ortega’s wife and spokeswoman, is the real force behind his administration.

In Panama there are grounds for concern because, “there’s very little check on Martinelli’s power,” says Michael Shifter, president of the Inter-American Dialogue in Washington DC.

Eisenmann, who was exiled twice for speaking out during Panama’s dictatorship under the Democratic Revolutionary Party (PRD), has gone to surprising lengths to avoid an Arias victory. He and a group focused on removing Martinelli are supporting the PRD, and they say their research shows its candidate, former Panama City mayor Juan Carlos Navarro, is most likely to defeat the incumbent party. Polls show Mr. Navarro is just behind Arias, though the race is practically neck-and-neck.

Panama’s Vice President Juan Carlos Varela, who publicly fell out with Martinelli halfway through his administration, represents Panama’s center-right Panamanista Party and is third in the polls, though he’s made significant gains in the past week.

'Vote against corruption'

During Martinelli’s term, Panama notched double-digit economic growth rates, largely credited to an ambitious $15 billion public investment program, including the $5.25 billion expansion of the Panama Canal and the construction of Central America’s first metro, which Martinelli unveiled last month. He gifted free rides until after the election.

Voters give Martinelli a 60 percent approval rating. Most analysts expect a continuation of his policies, including more infrastructure projects and social programs, such as paying Panamanians above 70 years old $120 a month. Though economic growth has slowed, the World Bank still expects it to be Latin America’s highest this year at around 7 percent. Unemployment last year was at a record 4.1 percent.

This is an election not of policy, analysts say, but on Martinelli’s personality. Supporters say the unconventional self-made millionaire, who campaigned by calling himself "el loco," or “the crazy one,” has slashed the bureaucracy that bogs down many Latin American countries and accomplished “more in four years than 40,” Martinelli’s favorite catch phrase.

Even so, there are still problems in Panama. The capital city is full of gleaming skyscrapers that often invite comparisons to Dubai, however, many seem empty or half-built. It leads some to believe that Panama hasn’t yet shed its reputation as a money-laundering hub, including for Colombian drug cartels.

Outside of the capital, home to about a third of Panama’s 3.8 million people, many live in poverty. The gap between rich and poor is one of the greatest in Latin America.

Critics say Panama’s weak justice system worsened under Martinelli, who now controls both the legislature and the judiciary, appointing three of five supreme court justices. The World Economic Forum rated Panama’s judicial independence at 132 out of 144 countries it evaluated in 2012.

Martinelli’s government has also faced accusations of accepting kickbacks in exchange for lucrative contracts, though he's dismissed such claims. Still, Panama slipped from 83rd to 102nd place in Transparency International’s annual corruption ranking last year.

“A vote against Martinelli is very much a vote against corruption,” says Ms. Grais-Targow, the Eurasia analyst. “Corruption is an issue in Panama normally but it’s become a much more pronounced issue under Martinelli.”

Voters say rising inflation is their biggest concern. Jessenia Gonzalez, an administrative assistant and mother of two, says food prices are skyrocketing. She also worries about the weak public health and education systems, noting she and her husband, a taxi driver, break their budget to afford private options.

Though she loves Martinelli’s metro, which cut her crippling commute, it’s time for a change, Ms. Gonzalez says.

“Panamanians have suffered a lot to live in democracy,” she says. “We have to treasure that.”